A valve timing adjusting apparatus has a housing and a vane rotor to form
multiple fluid chambers, and a relative position of the vane rotor to the
housing is adjusted by the fluid pressure supplied into the fluid
chambers. A check valve is provided in a branched passage portion, so
that working fluid may not be pushed out from an advancing fluid chamber
to a low pressure side, even when the working fluid in the advancing
fluid chamber is temporally compressed to increase its fluid pressure due
to a torque change applied from a cam shaft to the vane rotor.