An evaporator comprising: a housing having a suction port connectable to a suction portion of a compressor in order to evaporate at least part of a droplet or misty working fluid in the housing by a suction effect of the compressor through the suction port, and an introduction port for introducing working fluid into the housing through the introduction port, the housing being configured by a side wall portion provided with the suction port, a top wall portion provided with the introduction port and a bottom wall portion, wherein a top plate having through holes provided in a portion corresponding to a first space and a bottom plate are provided in the housing, a first storage space temporarily storing working fluid introduced through the introduction port is configured between the top plate and the top wall portion, and a filter installed between the top plate and the bottom plate in the housing, the filter dividing a space in the housing into the first space, into which working fluid in the first storage space is shed through the through holes, for generating the droplet or misty working fluid and a second space for communicating with the suction port, the filter being inclined away from the suction port as advancing upward, the filter transmitting therethrough vapor resulting from evaporation of the droplet or misty working fluid while capturing the droplet or misty working fluid, wherein a second storage space is configured between the bottom plate and the bottom wall portion to temporarily store working fluid shed from the first storage space, the stored working fluid in the second storage space being droplet or misty working fluid shed in the first space and flowing into the second storage space and working fluid captured by the filter and flowing into the second storage space, characterised in that the housing further comprises an exhaust port connectable to a pump in order to exhaust working fluid cooled down in the housing by the pump through the exhaust port, wherein the bottom wall portion is provided with the exhaust port, and the filter is connected to both the top plate and the bottom plate. a housing having a suction port connectable to a suction portion of a compressor in order to evaporate at least part of a droplet or misty working fluid in the housing by a suction effect of the compressor through the suction port, and an introduction port for introducing working fluid into the housing through the introduction port, the housing being configured by a side wall portion provided with the suction port, a top wall portion provided with the introduction port and a bottom wall portion, wherein a top plate having through holes provided in a portion corresponding to a first space and a bottom plate are provided in the housing, a first storage space temporarily storing working fluid introduced through the introduction port is configured between the top plate and the top wall portion, and a filter installed between the top plate and the bottom plate in the housing, the filter dividing a space in the housing into the first space, into which working fluid in the first storage space is shed through the through holes, for generating the droplet or misty working fluid and a second space for communicating with the suction port, the filter being inclined away from the suction port as advancing upward, the filter transmitting therethrough vapor resulting from evaporation of the droplet or misty working fluid while capturing the droplet or misty working fluid, wherein a second storage space is configured between the bottom plate and the bottom wall portion to temporarily store working fluid shed from the first storage space, the stored working fluid in the second storage space being droplet or misty working fluid shed in the first space and flowing into the second storage space and working fluid captured by the filter and flowing into the second storage space, characterised in that the housing further comprises an exhaust port connectable to a pump in order to exhaust working fluid cooled down in the housing by the pump through the exhaust port, wherein the bottom wall portion is provided with the exhaust port, and the filter is connected to both the top plate and the bottom plate.