No. Most parts of the cherimoya tree are poisonous, in fact only the delicious creamy white flesh is edible. In particular, discard the skin and the seeds. The seeds are like small black beans and show up well against the white flesh so there is little chance of eating one by mistake.
The seeds are toxic in a variety of ways and, although some effects are not serious, they are always best avoided. They have sometimes been used to create an insecticide.
But the flesh of the cherimoya was described by Mark Twain as 'Deliciousness itself'.