Provided is an oxygen concentration device which, in a purge step or a pressure equalization step thereof, reduces a difference in flow volume of gas flowing through a pressure equalization valve of a pressure equalization path. The device comprises a pressure control member wherein there is a difference of pressure loss according to a flow direction on at least one end side of the pressure equalization valve such that the pressure loss in one flow of gas flowing through the pressure equalization path and the pressure loss in the flow in the opposite direction are equivalent.本發明提供一種在氧濃縮裝置之吹掃步驟和均壓步驟時，使流通過均壓路徑之均壓閥的氣體流量差降低之氧濃縮裝置，其特徵在於在該均壓閥之至少一端側具備有因流動方向而有壓力損失差之壓力控制元件，使得流過均壓路徑之氣體的一方向流動之壓力損失等同於相反方向流動之壓力損失。
