To provide a testing device capable of recording desired log data indicating a device state and the like before/after triggering such as when abnormality occurs in a spot manner at a fine time interval, and a log data recording method for the same.

The testing device carrying out charge- or discharge testing for a sample includes first memory for sequentially overwriting oldest data with state information to execute loop recording if the state information acquired at given sampling time does not exceed a preset threshold value, and a second memory for sequentially recording state information if the state information exceeds a preset threshold value.