SWITCH DEVICE, CURRENT DETERMINATION METHOD AND COMPUTER PROGRAM

A load is detachably connected to a device connector of a switch device. A resistance value of a switch circuit when a sub-switch is ON is greater than an ON resistance value of a main switch. A microcomputer acquires node voltage information indicating a node voltage of a connection node located downstream of the main switch and the sub-switch from a voltage detection unit in a state where the main switch is OFF and the sub-switch is ON. The microcomputer determines whether a switch current that flows via the main switch when the main switch turns ON will be less than a current threshold value, based on the acquired node voltage information.