An inkjet recording device and a method for controlling an inkjet recording device are provided. A heating device that heats the ink to be supplied to a nozzle immediately ahead of the nozzle, a thermometer that detects a temperature of the ink inside the heating device or after heating, a viscometer that detects a viscosity of the ink in a main ink container are provided. The heating device is driven using a detection value of the thermometer to control the temperature of the ink such that the viscosity reaches an ink viscosity which enables normal printing, and when the viscosity of the ink is out of a range which enables printing, the solvent or the replenishment ink is supplied to the main ink container using a detection value of the viscometer such that the viscosity reaches the range which enables normal printing.