a body configured to be attached to a given region of a user;

a glucose sensor having a micro needle protruding from one surface of the body and configured to be inserted into an epidermis of the user; and

a glucose monitoring module for monitoring glucose from the glucose sensor, wherein the body comprises: a series of casings having a shape of a circular plate;

an attachment plate disposed on one surface of the series of casings and configured to be attached to the given region of the user;

an adhesion pad disposed on an underside of the attachment plate,

a button to be pressurized downward from a center of the series of casings;

a stepped protrusion for restricting an up and down moving distance of the button from the series of casings;

an elastic member adapted to elastically support the button against the stepped protrusion;

a locking projection protruding from the attachment plate to lock the underside of a substrate of the glucose sensor onto the attachment plate; and

a connection terminal connected to the glucose monitoring module when the glucose sensor is located on top of the locking projection of the attachment plate,

wherein the glucose sensor comprises: the micro needle including a conductive core having an outer peripheral surface, a lower end of the conductive core, a upper end of the conductive core, and an oxide layer coated on the entire outer peripheral surface of the conductive core except end portions of the conductive core including the lower end and the upper end of the conductive core; the substrate allowing an upper end of the micro needle to protrude upward therefrom and the lower end of the conductive core to protrude outward therefrom; a conductive member coatedly connected from top of the substrate to the oxide layer; a source electrode disposed at one side of the conductive member; a drain electrode disposed at the other side of the conductive member; an insulation layer coated on top of the conducive member to connect the source electrode and the drain electrode; and a gate electrode disposed at the upper end of the conductive core of the micro needle to allow the source electrode and the drain electrode to be spaced apart from top of the insulation layer,

wherein the glucose monitoring module comprises: a voltage applicator connected between the gate electrode of the glucose sensor and the glucose monitoring module; an electric current detector connected to a space between the source electrode and the drain electrode to detect an electric current; a voltage converter for converting the electrical current of the electric current detector into a voltage; a voltage amplifier for amplifying the voltage of the voltage converter; a signal converter for converting an analog signal of the voltage of the voltage amplifier into a data signal; a controller for identifying the data signal of the signal converter; and a radio communication module for transmitting the data signal of the controller outside, and

wherein one of the end portions of the conductive core of the micro needle including the upper end of the conductive core which is being protruded upward from the substrate is uncoated with the oxide layer such that electrons move to the conductive members along the micro needle to generate an electric current between the source electrode and the drain electrode when a predetermined voltage is applied to the gate electrode.