A water purification apparatus includes a main body having an accommodation chamber inside and a plate on a top side thereof, a lid pivotally mounted on the main body and closable on the main body, a holder mounted with the plate of main body and defining with the plate of the main body a distance, a top cover pivotally mounted with the holder and having a retaining portion, an inlet and an outlet opposite to the inlet, and a housing having a jamming portion detachably engageable with the retaining portion of the top cover, a first water filler hole in communication with the inlet of the top cover and a second water filler hole in communication with the outlet of the top cover. The water purification apparatus has the advantages of being convenient to exchange a filter.