The present invention relates to an oxygen concentrator in which a pulsation detection device for detecting pulsation of oxygen supplied and a control device for controlling an amount of air supplied from a compressor based on the detection results in a pressure swing adsorption-type oxygen concentrator, which is equipped with an adsorption bed filled with an adsorbent capable of selectively adsorbing nitrogen relative to oxygen, the compressor for supplying air to the adsorption bed, a channel switching valve to repeat in a constant timing an adsorption step, in which air is supplied from the compressor to the adsorption bed to isolate concentrated oxygen and a desorption step, in which the adsorption bed is evacuated to regenerate the adsorbent and a flow rate measuring device for determining a supply flow rate of concentrated oxygen produced and an amount of oxygen produced is controlled by a feedback with a flow rate sensor by itself after paying attention to variation of a product flow rate caused by suppressing an amount of oxygen produced, thereby realizing an apparatus to satisfy secondary performance such as miniaturization, low power consumption and silencing.
