An accumulator adapted to be arranged at a suction side of a compressor in a refrigerant circuit, separates a refrigerant into a gas and liquid, and stores the liquid refrigerant, the accumulator comprising: a pressure vessel which forms an inside space; an inflow port of the refrigerant and an outflow port of the refrigerant which are provided in a top part of the pressure vessel; a conduit which guides the refrigerant in the pressure vessel to the outflow port and which extends vertically downward under the outflow port and a gas-liquid separating means comprising a separating plate which is arranged in the pressure vessel facing the inflow port and spreads out substantially horizontally and perpendicular to a flow line at the inflow port; wherein the gas-liquid separating means has a peak shaped protrusion which has a single crest projecting out in the direction of the inflow port and a slanted surface on the separating plate at a region facing the inflow port, wherein an inside surface of the pressure vessel which faces the separating plate extends in parallel to the separating plate, and a gap (g) between the separating plate and the inside surface of the pressure vessel is 1/4 to 1 times the inside diameter of the inflow port, wherein the gas-liquid separating means has a circumferential wall part running around the separating plate so as to define a space which opens at the opposite side to the inflow port and a circumferential wall gap between the circumferential wall part and an inner circumferential surface of the pressure vessel, and the circumferential wall part extending downward from an outer circumferential part of the separating plate, and wherein an inlet of the conduit is arranged in the space defined by the gas-liquid separating means, and wherein a gaseous refrigerant passes through the circumferential wall gap and wherein a liquid phase refrigerant and oil which is contained in the refrigerant deposit on a front surface of the gas-liquid separating means and an inside surface of the pressure vessel and drip downward from there. a pressure vessel which forms an inside space; an inflow port of the refrigerant and an outflow port of the refrigerant which are provided in a top part of the pressure vessel; a conduit which guides the refrigerant in the pressure vessel to the outflow port and which extends vertically downward under the outflow port and a gas-liquid separating means comprising a separating plate which is arranged in the pressure vessel facing the inflow port and spreads out substantially horizontally and perpendicular to a flow line at the inflow port; wherein the gas-liquid separating means has a peak shaped protrusion which has a single crest projecting out in the direction of the inflow port and a slanted surface on the separating plate at a region facing the inflow port, wherein an inside surface of the pressure vessel which faces the separating plate extends in parallel to the separating plate, and a gap (g) between the separating plate and the inside surface of the pressure vessel is 1/4 to 1 times the inside diameter of the inflow port, wherein the gas-liquid separating means has a circumferential wall part running around the separating plate so as to define a space which opens at the opposite side to the inflow port and a circumferential wall gap between the circumferential wall part and an inner circumferential surface of the pressure vessel, and the circumferential wall part extending downward from an outer circumferential part of the separating plate, and wherein an inlet of the conduit is arranged in the space defined by the gas-liquid separating means, and wherein a gaseous refrigerant passes through the circumferential wall gap and wherein a liquid phase refrigerant and oil which is contained in the refrigerant deposit on a front surface of the gas-liquid separating means and an inside surface of the pressure vessel and drip downward from there.