A detection device is for detecting a passage timing of a turbine blade. This detection device is provided with: a sensor including a magnet and a coil that is disposed at a position subject to magnetic flux generated by the magnet and is configured to detect an induced electromotive force based on a change in the magnetic flux accompanying passage of the turbine blade; and an analyzer configured to detect the passage timing of the turbine blade, on the basis of an integrated signal obtained by integrating a signal based on the induced electromotive force.