An inkjet printer includes an inkjet head configured to perform printing on a printing sheet by use of ink. The inkjet printer includes: a heater configured to heat the ink; a thermometer configured to measure the temperature of the ink; and a controller configured to control the amount of electric power to be supplied to the heater and to control the inkjet head. In a case where the measured value of the ink temperature measured by the thermometer is in a range of a first reference temperature inclusive to a second reference temperature exclusive, the controller calculates a coverage rate of a page to be printed, and accordingly changes the amount of electric power to be supplied to the heater depending on the coverage rate thus calculated.