Waveform monitor apparatus of injection molding machine

A waveform monitor apparatus of an injection molding machine for monitoring an operation waveform at least during molding, which is mounted on the injection molding machine which performs molding according to a specific molding system where a predetermined clearance (a parting opening) occurs between a movable mold and a fixed mold in a mold at an injecting and filling time and an injection pressure (molding injection pressure) and a mold clamping force (molding mold clamping force) which can mold a good product are obtained and set, a mold clamping apparatus is mold-clamped by the molding mold clamping force, and resin is injected and filled into the mold by driving an injection apparatus where the molding injection pressure has been set as a limit pressure, wherein the waveform monitor apparatus of an injection molding machine comprises a parting opening detecting means for detecting change data of the parting opening to a time during molding, and an operation waveform displaying means for displaying at least change data from resin filling start into the mold to a cooling time termination of the mold detected by the parting opening detecting means on a waveform displaying portion on a screen of a display attached to a molding machine controller.