A push switch and mounting substrate arrangement comprising a mounting substrate and a push switch provided at a side edge of the mounting substrate which does not have a cutout thereof, the push switch comprising: a switch substrate (2, 7) having an L-shaped cross section, wherein said substrate has a front surface located perpendicular to a mounting surface of said mounting substrate, a back surface for mounting on said mounting substrate, and a side face for facing to said front surface; an accommodating recess provided on said front surface; a center contact provided so as to be substantially centralized in said accommodating recess; a pair of peripheral contacts each provided at a circumferential edge of said accommodating recess; a movable contact spring constructed so as to extend across said pair of peripheral contacts and designed to be brought into contact with said center contact when pressed; a connection pad (15A, 15B, 19) provided on said back surface and electrically connected to said mounting substrate; and an electrode (17A, 17B, 18) provided on said side face and electrically connected to said connection pad; wherein said switch substrate has a second side face other than said side face, and said second side face has a channel of an arc-shaped cross section, and wherein said switch substrate includes a first substrate which is bonded to said side edge of said mounting substrate, and a second substrate which is connected perpendicular to said first substrate so as to provide said L-shaped cross section and to provide connection of the peripheral contacts on the first substrate to connection patterns (14A, 14B) on the second substrate, and which has said connection pad. a switch substrate (2, 7) having an L-shaped cross section, wherein said substrate has a front surface located perpendicular to a mounting surface of said mounting substrate, a back surface for mounting on said mounting substrate, and a side face for facing to said front surface; an accommodating recess provided on said front surface; a center contact provided so as to be substantially centralized in said accommodating recess; a pair of peripheral contacts each provided at a circumferential edge of said accommodating recess; a movable contact spring constructed so as to extend across said pair of peripheral contacts and designed to be brought into contact with said center contact when pressed; a connection pad (15A, 15B, 19) provided on said back surface and electrically connected to said mounting substrate; and an electrode (17A, 17B, 18) provided on said side face and electrically connected to said connection pad; wherein said switch substrate has a second side face other than said side face, and said second side face has a channel of an arc-shaped cross section, and wherein said switch substrate includes a first substrate which is bonded to said side edge of said mounting substrate, and a second substrate which is connected perpendicular to said first substrate so as to provide said L-shaped cross section and to provide connection of the peripheral contacts on the first substrate to connection patterns (14A, 14B) on the second substrate, and which has said connection pad.