A sensor device comprising: a rod member including an axially extending fluid passage, the fluid passage being formed inside the rod member and configured such that fluid flows into the fluid passage; a temperature sensor having a rod shape and thinner than the fluid passage, the temperature sensor being inserted in the fluid passage with a distal end of the temperature sensor being located inside the fluid passage, the temperature sensor being configured to detect a temperature of the fluid; a pressure sensor communicating with the fluid passage, the pressure sensor being configured to detect a pressure of the fluid; wherein the fluid passage is configured such that the fluid flows from the distal end of the temperature sensor toward a proximal end of the temperature sensor, the fluid passage includes a helically shaped passage disposed upstream of a location in communication with the pressure sensor, and a linear passage continuous to an upstream side of the helically shaped passage, the sensor device furthermore comprising a fixing member configured to fix the proximal end of the temperature sensor; and a retention member (31,35), wherein the retention member (31, 35) is disposed in the linear passage, the retention member (31, 35) includes an upstream retention member that retains the distal end of the temperature sensor and blocks the linear passage, and a downstream retention member that retains a portion of the temperature sensor closer to the proximal end than the distal end and blocks the linear passage, a communication hole into which the fluid is allowed to flow is disposed in a side portion of the rod member corresponding to the linear passage between the upstream retention member and the downstream retention member, and a communication hole into which the fluid is allowed to flow is disposed in a side portion of the rod member corresponding to the linear passage downstream of the downstream retention member. a rod member including an axially extending fluid passage, the fluid passage being formed inside the rod member and configured such that fluid flows into the fluid passage; a temperature sensor having a rod shape and thinner than the fluid passage, the temperature sensor being inserted in the fluid passage with a distal end of the temperature sensor being located inside the fluid passage, the temperature sensor being configured to detect a temperature of the fluid; a pressure sensor communicating with the fluid passage, the pressure sensor being configured to detect a pressure of the fluid; wherein the fluid passage is configured such that the fluid flows from the distal end of the temperature sensor toward a proximal end of the temperature sensor, the fluid passage includes a helically shaped passage disposed upstream of a location in communication with the pressure sensor, and a linear passage continuous to an upstream side of the helically shaped passage, the sensor device furthermore comprising a fixing member configured to fix the proximal end of the temperature sensor; and a retention member (31,35), wherein the retention member (31, 35) is disposed in the linear passage, the retention member (31, 35) includes an upstream retention member that retains the distal end of the temperature sensor and blocks the linear passage, and a downstream retention member that retains a portion of the temperature sensor closer to the proximal end than the distal end and blocks the linear passage, a communication hole into which the fluid is allowed to flow is disposed in a side portion of the rod member corresponding to the linear passage between the upstream retention member and the downstream retention member, and a communication hole into which the fluid is allowed to flow is disposed in a side portion of the rod member corresponding to the linear passage downstream of the downstream retention member.