Abstract: A refrigerant condenser is set so that, if its condensation distance is L, the equivalent diameter of a tube having a linearly configured passage for the purpose of heat exchange is de (each dimension being in units of mm), and the number of times the direction change of the linearly configured passage for the purpose of heat exchange change is N, with de.ltoreq.1.15 and the relationship L=(N+1)W=400+1,180 de to 700+1,180 de satisfied, a high heat exchange efficiency is achieved. In this refrigerant condenser, it is possible to use a single long winding tube.