The present invention provides an exposure apparatus that can prevent the degradation of exposure and measurement accuracies. An exposure apparatus (EX) exposes a substrate (P) by irradiating the substrate (P) with exposure light (EL) through a projection optical system (PL) and a liquid (LQ), and comprises: a liquid supply mechanism (10) that supplies the liquid (LQ) between an optical element (2) at the image plane side tip part of the projection optical system (PL) and a substrate (P) that opposes the optical element (2); a timer (60) that measures the time that has elapsed since the supply of the liquid by the liquid supply mechanism (10) was started; and a control apparatus (CONT) that determines, based on a measurement result of the timer (60), whether a space(SP), which is between the optical element (2) and the substrate (P) and includes at least an optical path of the exposure light (EL), is filled with the liquid (LQ).