An electric connection socket for relaying electric signals between a circuit substrate and an electric component includes: a metal housing which has a through hole enabling communication between the top surface and the bottom surface thereof, and on the top surface of which the electric component is mounted and on the bottom surface of which the circuit substrate is mounted; and a signal pin inserted into the through hole to configure a coaxial line between the inner wall surfaces of the through hole, and which is electrically connected at one end to a signal path first pad electrode of the circuit substrate and is electrically connected at the other end to a signal path terminal of the electric component. On the bottom surface, the metal housing has a ground connection unit which contacts a second pad electrode for grounding formed on the circuit substrate and which grounds the metal housing.