A valve device, comprising: a drive source; a turning member, being driven and turned by the drive source; a valve body, being fixed to the turning member in a state that an end face of the valve body and an end face of the turning member in an axial direction are contacted with each other, and the valve body is integrally turned with the turning member; and a valve seat, being sliding contacted with an end face of the valve body opposite to the end face of the valve body contacting with the turning member; wherein the valve seat comprises at least one outflow hole (22, 221, 222) for fluid passing through the valve device; wherein the valve body comprises a throttle part which is a minute hole capable of being communicated with the outflow hole (22, 221, 222) in a part of a turning angle of the valve body; and wherein a flow passage comprises an opening part which is provided between opposed faces of the turning member and the valve body, so that the throttle part is communicated with an inflow hole for the fluid, wherein the valve device characterized in that: the flow passage is a stepped part formed in an outer circumferential edge of the opposed face of the valve body or an outer circumferential edge of the opposed face of the turning member, a height in an axial direction of the opening part of the stepped part is smaller than a minimum diameter of the throttle part, and a length in a circumferential direction of the opening part of the stepped part is set to be a length so that an area of the opening part obtained by multiplying the length by the height in the axial direction is larger than an opening area of the throttle part. a drive source; a turning member, being driven and turned by the drive source; a valve body, being fixed to the turning member in a state that an end face of the valve body and an end face of the turning member in an axial direction are contacted with each other, and the valve body is integrally turned with the turning member; and a valve seat, being sliding contacted with an end face of the valve body opposite to the end face of the valve body contacting with the turning member; wherein the valve seat comprises at least one outflow hole (22, 221, 222) for fluid passing through the valve device; wherein the valve body comprises a throttle part which is a minute hole capable of being communicated with the outflow hole (22, 221, 222) in a part of a turning angle of the valve body; and wherein a flow passage comprises an opening part which is provided between opposed faces of the turning member and the valve body, so that the throttle part is communicated with an inflow hole for the fluid, wherein the valve device characterized in that: the flow passage is a stepped part formed in an outer circumferential edge of the opposed face of the valve body or an outer circumferential edge of the opposed face of the turning member, a height in an axial direction of the opening part of the stepped part is smaller than a minimum diameter of the throttle part, and a length in a circumferential direction of the opening part of the stepped part is set to be a length so that an area of the opening part obtained by multiplying the length by the height in the axial direction is larger than an opening area of the throttle part. the flow passage is a stepped part formed in an outer circumferential edge of the opposed face of the valve body or an outer circumferential edge of the opposed face of the turning member, a height in an axial direction of the opening part of the stepped part is smaller than a minimum diameter of the throttle part, and a length in a circumferential direction of the opening part of the stepped part is set to be a length so that an area of the opening part obtained by multiplying the length by the height in the axial direction is larger than an opening area of the throttle part.