A stacking connector is formed by a connector main body and a plug substrate, the connector main body has a substrate sandwiching member including a sandwiching gap into which the plug substrate fits, and a projection projecting into the sandwiching gap, the plug substrate has a concavity with which the projection engages in both top and bottom surfaces, and, after inserting the plug substrate into the sandwiching gap of the substrate sandwiching member, by sliding the plug substrate in a direction at right angles to the insertion direction, the concavity engages with the projection and the plug substrate is linked to the connector main body in an unremovable state.