a first terminal including a first connecting portion;

a second terminal including a second connecting portion; and

a spring member for sandwiching the first and second connecting portions in an overlapped state,

wherein:

at least one of contact surfaces of the first and second connecting portions has a contact point portion in the form of a curved surface bulging toward the other contact surface,

the spring member includes a pressing point for pressing the first and second connecting portions in an overlapping direction at a position separated from the contact point portion,

the spring member includes a pair of pressing pieces to be respectively overlapped on the first and second connecting portions from both sides in the overlapping direction and a coupling portion coupling the pair of pressing pieces, and at least one of the pressing pieces includes two pressing points shaped to bulge toward the other pressing piece at two positions separated from each other across the contact point portion,

the pressing piece of the spring member includes a slit extending between the two pressing points and open in a projecting end of the pressing piece,

the spring member includes the pressing points at two positions separated across the contact point portion in a direction orthogonal to the overlapping direction of the first and second connecting portions, and

the two pressing points are made mutually independently displaceable by the slit.