To provide a connection pin which reduces the number of parts and cost.

A connection pin 100 comprises: a conductive cylindrical barrel 110; and a conductive coil spring 120. The coil spring 120 has a close wound connecting portion 121 housed and fixed to the inside of the barrel 110, a close wound contacting portion 122, and a coarsely wound elastic deformation portion 123 provided between the connecting portion 121 and the contacting portion 122 and housed in the barrel 110. The contacting portion 122 has a first end portion 122a housed in the barrel 110 so as to form a clearance and a second end portion 122b extending from an open end portion 111 of the barrel 110. When external force is applied to a tip section 122b1 of the second end portion 122b, the elastic deformation portion 123 elastically deforms and the first end portion 122a comes in contact with an inner peripheral surface of the barrel 110.