Abstract: An electronic apparatus includes: an outer casing in which an air inflow hole allowing outside air to flow into internal space and a heat releasing hole releasing air temperature of which has been increased in the internal space to the outside are formed; a circuit substrate arranged in the internal space of the outer casing and on which electronic components to be heat sources at the time of driving are mounted; and a heat sink having an attachment base attached to the circuit substrate and plural fins protruding from the attachment base, wherein the outer casing is provided with fluid guide portions positioned opposite to the plural fins of the heat sink and guiding the air with increased temperature, the fluid guide portions are inclined in directions toward the heat releasing hole and the plural fins are inclined to directions toward the heat releasing hole.