To provide an endoscope instrument which permits the voltage sensing function to properly work even if residual voltage in the endoscope instrument is naturally discharged in a standby condition.

The endoscope instrument 1 has a first voltage sensing section 102 for which a first threshold voltage value is set to sense a variation in the voltage value of a driving power source and a second voltage sensing section 103 for which a second threshold voltage value lower than the first threshold value is set to sense a variation in the voltage value of the driving power source. The second voltage sensing section 103 changes a sensed voltage value set to sense that the voltage value of the driving power source becomes lower than the first threshold voltage value to a prescribed voltage value lower than the lower voltage value of the driving power source when the voltage value of the driving power source becomes lower than the first threshold voltage value and then lower than the second threshold voltage value, and makes the first voltage sensing section sense a variation in the voltage value of the driving power source on the basis of the changed prescribed voltage value.