A blender includes a container mounted removably on a housing for containing food items and provided with a cutting blade unit that is to be driven rotatably by a motor unit when the container is mounted on the housing. A control unit is operable in accordance with an initial control signal from a switch unit so as to activate the motor unit to operate in a judgment mode. The control unit determines food processing conditions in accordance with a motor rotation signal generated by a sensor unit for indicating a rotary speed of the motor unit when the motor unit is operated in the judgment mode. The control unit switches operation of the motor unit from the judgment mode to a food processing mode upon determining the food processing conditions so as to drive rotation of the cutting blade unit to blend the food items contained in the container.