To provide a valve timing adjusting device which can be easily manufactured, and achieve stable driving by reducing leakage of working fluid within the device.

A housing 11 includes: a cylindrical circumferential wall 130; shoes 131-134 extending radially inward from the circumferential wall 130; and side walls disposed on both ends of the circumferential wall 130. A vane rotor 16 includes a rotor 60 disposed inside the circumferential wall 130 and forming a pressure chamber 50 between the circumferential wall 130 and the shoes 131-134 and the side walls; and vanes 61-64 for partitioning the pressure chamber 50 into a retard chamber and an advance chamber. The vane rotor can be rotated relative to the housing 11 by the pressure of the working fluid supplied to the pressure chamber 50. A seal member 20 has a dense section 21 made of a coil-shaped wire rod and formed so that the space between the wires of the wire rod becomes substantially zero. A shaft is disposed between the vanes 61-64 and the circumferential wall 130 to be substantially parallel to the rotary shaft of the vane rotor 16, thereby providing a fluid-tight holding between the retard chamber and the advance chamber.