According to one embodiment, a substrate processing apparatus and a substrate processing method that can improve the quality of substrates are provided. The substrate processing apparatus according to one embodiment includes: a table 20 configured to support a processing target W including a substrate W1, a ring W2 surrounding a surrounding of the substrate W1, and a dicing tape W3 adhered to a lower surface of the substrate W1 and a lower surface of the ring W2, and a liquid supplier 50 configured to eject a liquid which does not mix with a processing liquid for processing the substrate W1 and which has a specific gravity heavier than the processing liquid to one of an upper surface of the ring W2 of the processing target W supported by the table 20 rotating by the rotation mechanism 30, an outer circumference end portion of the substrate W1 of the processing target W supported by the table 20 rotating by the rotation mechanism 30, and between the substrate W1 and the ring W2 of the processing target W supported by the table 20 rotating by the rotation mechanism in accordance with a rotation number of the table 20 to supply the liquid between the substrate W1 and the ring W2 of the processing target W.