PHYSICAL-QUANTITY DETECTION DEVICE

In order to improve sensor characteristics and minimize variation in said characteristics, a pressure sensor is positioned upstream of a humidity sensor so as to help prevent water from contacting the humidity sensor and dust from adhering to the humidity sensor. This physical-quantity detection device 300 is characterized by having a detection unit 422 that detects humidity, a detection unit 421 that detects pressure, a circuit board 400 that has an electronic circuit that processes detection signals, and a housing 302 that accommodates the circuit board 400. The physical-quantity detection device 300 is also characterized in that the detection units 422, 421 are laid out on the surface of the circuit board 400 in a straight line in the direction in which a gas being measured flows, with the detection unit 421 that detects pressure positioned upstream of the detection unit 422 that detects humidity.