An object of the present invention is to provide a moisture measuring apparatus which, when the body of the apparatus for measuring a state of moisture in a measurement target object is mounted into the measurement target object, provides a user with a mounting state as to whether the moisture measuring apparatus has been appropriately mounted. In the present invention, the CPU of a moisture measuring apparatus determines the mounting state of the moisture measuring apparatus in soil that is a measurement target object (judges whether or not there is a gap between a sensor electrode and soil) based on the state of moisture (moisture amount) measured by a soil moisture amount sensor, and informs a result of the judgment.