The present invention comprises: a cylindrical pipe (314) that has a cylindrical shape about an axis (O) extending in the horizontal direction and has a space internally extending in the direction of the axis (O); steam inlets (31, 32) which are provided at the bottom of the cylindrical pipe (314) and through which steam is introduced; a steam outlet (33) that is opened from an end of the cylindrical pipe (314) in the axis (O) direction toward the axis (O) direction for exhausting steam from the cylindrical pipe (314); and a moisture separation element (315) that is provided in the cylindrical pipe (314) between the steam inlets (31, 32) and the steam outlet (33) and has a plurality of vanes for separating moisture from steam by passing the steam through the vanes.