Abstract: A voltage measuring sheet which is capable of qualitatively measuring the existing strength of condition of batteries has an electrically conductive layer and a temperature-sensitive decoloring type coloring layer which are provided on a transparent substrate. The sheet further has contacts defined by the conductive layer which are brought into contact with two electrodes, respectively, of a battery which is to be measured. In addition, a scale pattern is disposed underneath the coloring layer. Thus, it is possible to simplify the arrangement and hence production of the sheet and facilitate the reading of indication on the sheet.