Abstract: An abdominal exerciser that can be conveniently applied on the abdomen of a user who is laying down flat is provided. By pushing the abdominal exerciser up and down using the abdominal muscles, abdominal muscles become tones and excess fat can be reduced. The abdominal exerciser includes a flexible plate having a plurality of projections on the bottom surface, for pushing the abdomen down by gravity, and a weigh applying means fixed to the top surface of the flexible plate, for applying its weight to the abdomen.