Device for checking spark plugs, can be made from a used or unnecessary piezoelectric lighter. For this, the lighter must be disassembled and pulled out the piezoelectronic unit, extend its wire by a few centimeters and insulate. This wire is connected to the upper contact of the candle, and the block body to the candle body. The button is pressed, if the spark slips between the electrodes, then the candle is good, if it drains or is absent, then it is broken.