The invention relates to a respiratory device for keeping a patient breathing artificially or support his or her breathing naturally. Said respiratory device comprises an air inlet, an air source, and at least one proportionally adjustable control valve. The control valve is provided with a housing (11) and a rotary valve (12) which is arranged in the housing so as to be twistable about the longitudinal axis thereof and which allows through-holes (11d) of the housing (11) to be entirely or partially closed by twisting the rotary valve (12). The rotary valve (12) and a corresponding support surface (11f) of the housing (11) have a conical shape, the support surface (11f) cooperating with the rotary valve (12). The through-holes (11d) are disposed in the area of the support surface (11f).