According to one embodiment, a semiconductor manufacturing apparatus includes a manufacturing processor, a signal acquisition unit, a frequency characteristic acquisition unit, and an end-point acquisition unit. The signal acquisition unit acquires a first processing signal which shows a different behavior during processing of a stacked body and after the processing of the stacked body. The frequency characteristic acquisition unit acquires a frequency characteristic of a noise caused by a periodic structure of the stacked body from the first processing signal during the processing of the stacked body. The end-point acquisition unit detects an end point of the processing using the acquired frequency characteristic. The manufacturing processor ends the processing when the end point is detected.