A cooling apparatus (1) has a compressor (2), a condenser (3), an expansion valve (5), an evaporator (6) and an electric valve (10), all connected to each other in this order by a piping line to form a refrigeration circuit. The apparatus further has a heating section (11) and a bypass (12), and a thermosensitive tube (13) of the expansion valve is disposed between the heating section (11) and the electric valve (10) so that temperature of a refrigerant having left this section is detected before entering this valve (10). The refrigerant remains as a gas-liquid mixture until it leaves the evaporator (6) such that temperature of the refrigerant is uniform within the evaporator and equal to the saturation vapor temperature of this refrigerant, and therefore fluctuation in the refrigerant temperature is diminished.