Abstract: The present invention relates to a receiver-drier for separating liquid and gaseous refrigerant and removing moisture and impurities in the refrigerant, in which the lower cap is exactly assembled to the receiver-drier so as to air-tightly close a lower opening of the receiver-drier when the lower cap is screwed to the receiver-driver, thereby preventing a leakage and also facilely performing the assembling. The structure includes a receiver-drier tank having an opening at a lower end thereof; a body which is inserted into the opening to be screwed to the receiver-drier tank; a filter which is disposed at an upper side of the body to have a flange portion for assisting in exactly assembling the body and filter; and a sealing member which is provided at a junction portion between the body and the filter so as to air-tightly close the receiver-drier tank.