Disclosed is a reaction method that includes a reaction process using a pipette tip to allow substances to cause a reaction, the method including: providing a heater for heating the pipette tip in accordance with a preset temperature; attaching the pipette tip to a pipette nozzle and heating the pipette tip by a first preset temperature; when a period of heating by the first preset temperature exceeds a preset period, switching an output of the heater from the first preset temperature to a lower second preset temperature; detecting a distal end position of the pipette tip at or after the switching; and executing the reaction process while controlling the distal end position of the pipette tip with reference to the detected distal end position, in which the temperature of the pipette tip is kept by the second preset temperature at least until operation of the pipette tip.