A refrigeration cycle apparatus, comprising: a refrigerant circuit formed by connecting, by a refrigerant pipe, a compressor, a condenser, an expansion device, an evaporator, and a liquid reservoir (15, 150, 150B-150E); and a liquid level detection sensor provided in the liquid reservoir (15, 150, 150B-150E), the liquid reservoir (15, 150, 150B-150E) comprising a container configured to accumulate the refrigerant; and an inlet pipe having a discharge outlet portion formed on an inlet side to the container for the refrigerant, being connected to the refrigerant circuit, and being configured to allow a portion of the refrigerant outside of the container to flow into the container, characterised in that the liquid level detection sensor includes a plurality of heat generating units and a plurality of temperature detection units, the heat generating units being paired with the temperature detection units, the liquid level detection sensor being configured to detect a liquid level of refrigerant accumulated in the liquid reservoir based on a temperature of the heat generating units, wherein in the container, when a conical closed space, which is formed between a preset position on a central axis of the discharge outlet portion and a distal end edge of an inner surface of the discharge outlet portion, and in which a flow velocity of the refrigerant becomes equal to or higher than a predetermined flow velocity, is defined as a core region, wherein the preset position on the central axis of the discharge outlet portion from the discharge outlet being set five times an inner diameter of the distal end edge of the inner surface of the discharge outlet portion for the refrigerant of the inlet pipe, the liquid level detection sensor is provided at a position other than the core region. a refrigerant circuit formed by connecting, by a refrigerant pipe, a compressor, a condenser, an expansion device, an evaporator, and a liquid reservoir (15, 150, 150B-150E); and a liquid level detection sensor provided in the liquid reservoir (15, 150, 150B-150E), the liquid reservoir (15, 150, 150B-150E) comprising a container configured to accumulate the refrigerant; and an inlet pipe having a discharge outlet portion formed on an inlet side to the container for the refrigerant, being connected to the refrigerant circuit, and being configured to allow a portion of the refrigerant outside of the container to flow into the container, a container configured to accumulate the refrigerant; and an inlet pipe having a discharge outlet portion formed on an inlet side to the container for the refrigerant, being connected to the refrigerant circuit, and being configured to allow a portion of the refrigerant outside of the container to flow into the container, characterised in that the liquid level detection sensor includes a plurality of heat generating units and a plurality of temperature detection units, the heat generating units being paired with the temperature detection units, the liquid level detection sensor being configured to detect a liquid level of refrigerant accumulated in the liquid reservoir based on a temperature of the heat generating units, wherein in the container, when a conical closed space, which is formed between a preset position on a central axis of the discharge outlet portion and a distal end edge of an inner surface of the discharge outlet portion, and in which a flow velocity of the refrigerant becomes equal to or higher than a predetermined flow velocity, is defined as a core region, wherein the preset position on the central axis of the discharge outlet portion from the discharge outlet being set five times an inner diameter of the distal end edge of the inner surface of the discharge outlet portion for the refrigerant of the inlet pipe, the liquid level detection sensor is provided at a position other than the core region.