In a coating pretreatment facility using microbubbles, an arrangement is made to make it possible to form the facility compact and to reduce the initial cost and the running cost of the facility. A preliminary cleansing water supplying passage 33 is provided for supplying cleansing waters W1, W2 used in cleansing of a coating subject article B in flushing sections 3, 4 following a degreasing section 2 as preliminary cleansing water W3 for use in preliminary cleansing of the coating subject article B in a preliminary cleansing section 1. A microbubble generator device 34 is provided for causing the preliminary cleansing water W3 used in the preliminary cleansing of the coating subject article B in the preliminary cleansing section 1 to contain microbubbles.