A physical quantity sensor is constituted using a lead frame having at least one stage and a plurality of leads whose bases are arranged in the same plane, wherein at least one physical quantity sensor chip having a plurality of electrode pads is mounted on the stage and is inclined so that the electrode pads are disposed in the inclination direction and are connected to the leads by use of wires whose lengths substantially match distances between the electrode pads and leads. This prevents the leads and wires from being unexpectedly broken, and it is possible to avoid the occurrence of separation of the leads from the physical quantity sensor chip. In addition, the tip ends of the leads are disposed along the surface of the inclined stage before wire bonding; hence, it is possible to easily connect the tip ends of the leads to the physical quantity sensor chip.