A non-volatile memory apparatus and a data verification method thereof are provided. The non-volatile memory apparatus includes a plurality of memory cells, a page buffer, a write circuit, a sense amplifier, and a sense and compare circuit. The page buffer stores a plurality of buffered data and programs the plurality of memory cells according to the plurality of buffered data. The write circuit receives a program data or a rewrite-in data and writes the program data or the rewrite-in data to the page buffer. The sense amplifier senses data read from the memory cells for generating a read-out data. The sense and compare circuit reads the buffered data, and compares the read-out data and a compared buffered data to generate a rewrite-in data. The sense and compare circuit determines the rewrite-in data to be the buffered data or an inhibiting data according to the compared result.