1. An electronic part housing structure, comprising:a heat sink including a heat sink base portion on an upper face side of which a depressed portion forming a refrigerant channel is provided and a heat sink upper plate caused to cover the depressed portion of the heat sink base portion, wherein the refrigerant channel is sealed using a seal portion provided in an outer peripheral portion of the heat sink upper plate;
an upper case caused to cover an upper face side of the heat sink;
an electronic part mounted on an upper face of the heat sink upper plate; and
a waterproofing wall provided between the electronic part and the seal portion in an internal space of the upper case and protruding from the upper face of the heat sink upper plate so as to enclose the electronic part.