A position detection device comprising: a first position obtaining unit that obtains position information by receiving a GPS (Global Positioning System) signal; a second position obtaining unit that obtains position information based on information obtained from a plurality of peripheral base stations; a position information obtainment determining unit that determines whether or not the first position obtaining unit obtains position information; a movement detection unit that detects a whether or not the first position obtaining unit is moved; a first state control unit that switches the first position obtaining unit off if the movement detection unit detects that the first position obtaining unit is not moved and the position information obtainment determining unit determines that the first position obtaining unit is not able to obtain position information, and that switches the first position obtaining unit on if the movement detection unit detects that the first position obtaining unit is moved when the first position obtaining unit is switched off; a second state control unit that switches the second position obtaining unit off when the position information obtainment determining unit determines that the first position obtaining unit obtains position information when the second position obtaining unit is switched on and that switches the second position obtaining unit on when the position information obtainment determining unit determines that the first position obtaining unit does not obtain position information; a monitor cycle control unit that controls a monitor cycle such that the first position obtaining unit obtains position information more frequently when the movement detection unit indicates the first position obtaining unit is moving, than when not moving; and an output unit that selects and outputs one of two pieces of position information obtained by the first position obtaining unit and the second position obtaining unit. a first position obtaining unit that obtains position information by receiving a GPS (Global Positioning System) signal; a second position obtaining unit that obtains position information based on information obtained from a plurality of peripheral base stations; a position information obtainment determining unit that determines whether or not the first position obtaining unit obtains position information; a movement detection unit that detects a whether or not the first position obtaining unit is moved; a first state control unit that switches the first position obtaining unit off if the movement detection unit detects that the first position obtaining unit is not moved and the position information obtainment determining unit determines that the first position obtaining unit is not able to obtain position information, and that switches the first position obtaining unit on if the movement detection unit detects that the first position obtaining unit is moved when the first position obtaining unit is switched off; a second state control unit that switches the second position obtaining unit off when the position information obtainment determining unit determines that the first position obtaining unit obtains position information when the second position obtaining unit is switched on and that switches the second position obtaining unit on when the position information obtainment determining unit determines that the first position obtaining unit does not obtain position information; a monitor cycle control unit that controls a monitor cycle such that the first position obtaining unit obtains position information more frequently when the movement detection unit indicates the first position obtaining unit is moving, than when not moving; and an output unit that selects and outputs one of two pieces of position information obtained by the first position obtaining unit and the second position obtaining unit.