A method for testing at least a first and a second test quantity of a tempering apparatus (31; 41), which serves to temper at least a sample, in particular a PCR-sample, in a tempering program by setting at least a setpoint temperature as a target temperature at at least one control circuit (32; 42; 42'), wherein this tempering apparatus comprises at least one tempering block, which is adapted for receiving the at least one sample, at least one first tempering device (38; 48; 48') and a second tempering device (39; 49; 49'), which are arranged for tempering this at least one tempering block, at least one first temperature measuring device (7'; 51; 51') and at least one second temperature measuring device (7; 50; 50'), wherein with each of the tempering devices at least one temperature measuring device is associated, at least one control device (8; 58) adapted for controlling the tempering of said at least one tempering block, and at least one first control circuit (32; 42; 42'), with which this at least one first tempering device (38; 48; 48') and this at least one first temperature measuring device (7'; 51; 51') associated with this at least one first tempering device (38; 48; 48') and this at least one second tempering device (39; 49; 49') and this at least one second temperature measuring device (7; 50; 50'), which is associated with this second tempering device (39; 49; 49'), are associated, wherein said at least one first temperature measuring device (7'; 51; 51') and said at least one second temperature measuring device (7; 50; 50') are associated with this at least one first control circuit (32; 42; 42') as measuring members, wherein the formation of the control variable of the at least one first control circuit (32; 42; 42') is performed by an average value formation of the actual temperature values, which are measured by said at least one first and at least one second temperature measuring device (7'; 51; 51'; 7; 50; 50'), and wherein a testing device (14', 54) for performing this method of testing is associated with said tempering apparatus, wherein this testing device (14'; 54) comprises electrical circuits, which are suitable for processing signals, which are necessary for performing this testing method, and a signal connection to each of these at least two temperature measuring devices (7'; 7; 51; 51'; 50; 50') serving as measuring members of said at least one first control circuit and to each of said tempering devices (38; 48; 48'; 39; 49; 49'), and wherein the method comprises the following steps: - starting said method; - operating at least this first tempering device (38; 48; 48') for a duration of at least a first time span beginning at least at a first time; - acquiring at least one measuring temperature from this at least one first temperature measuring device (7'; 51; 51') at least at a second time; - determining at least a first test quantity of the tempering apparatus by using this at least one measuring temperature; - operating this second tempering device (39; 49; 49') for the duration of at least a first time span beginning at least at a first time; - acquiring at least one measuring temperature from this at least one second temperature measuring device (7; 50; 50') at least at a second time; - determining at least a second test quantity of the tempering apparatus by using this at least one measuring temperature; - comparison of this first test quantity with the second test quantity. with which this at least one first tempering device (38; 48; 48') and this at least one first temperature measuring device (7'; 51; 51') associated with this at least one first tempering device (38; 48; 48') and this at least one second tempering device (39; 49; 49') and this at least one second temperature measuring device (7; 50; 50'), which is associated with this second tempering device (39; 49; 49'), are associated, - starting said method; - operating at least this first tempering device (38; 48; 48') for a duration of at least a first time span beginning at least at a first time; - acquiring at least one measuring temperature from this at least one first temperature measuring device (7'; 51; 51') at least at a second time; - determining at least a first test quantity of the tempering apparatus by using this at least one measuring temperature; - operating this second tempering device (39; 49; 49') for the duration of at least a first time span beginning at least at a first time; - acquiring at least one measuring temperature from this at least one second temperature measuring device (7; 50; 50') at least at a second time; - determining at least a second test quantity of the tempering apparatus by using this at least one measuring temperature; - comparison of this first test quantity with the second test quantity.