a heater that includes a plurality of heat-generating blocks arrayed in a width direction of a recording material that is orthogonal to a conveying direction of the recording material;

a nip forming portion forming a nip that nips the recording material;

a temperature-detecting portion that detects a temperature of the heater; and

a control portion that controls electric power to be supplied to the plurality of heat-generating blocks, based at least on the temperature detected by the temperature-detecting portion,

wherein the image heating apparatus heats an image formed on recording material nipped by the nip, by heat of the heater,

wherein the plurality of heat-generating blocks have a first heat-generating group and a second heat-generating group,

wherein the first heat-generating group includes first and fourth heat-generating blocks symmetrically laid out with a conveyance reference position of the recording material in the width direction as a reference, and the second heat-generating group includes second and third heat-generating blocks symmetrically laid out with the conveyance reference position, placed at positions in the width direction different from the positions at which the first and fourth heat-generating blocks are placed,

wherein the temperature-detecting portion includes at least one first temperature-detecting element for detecting the temperature of at least one of the first and fourth heat-generating blocks included in the first heat-generating group, and at least one second temperature-detecting element for detecting the temperature of at least one of the second and third heat-generating blocks included in the second heat-generating group,

wherein, in a case of heating the image formed on the recording material at the nip forming portion, the control portion supplies electric power via a first switch to the first heat-generating group to maintain a detected temperature detected by only one of the at least one first temperature-detecting element at a control target temperature, and supplies electric power via a second switch to the second heat-generating group to maintain a detected temperature detected by only one of the at least one second temperature-detecting element at a control target temperature,

wherein the only one of the at least one first temperature-detecting element is placed on one side as to the conveyance reference position in the width direction, and

wherein the only one of the at least one second temperature-detecting element is placed on other side as to the conveyance reference position in the width direction.