A laminated substrate separating device used for separating a first substrate from a second substrate of a laminated substrate is provided. The first and the second substrates are misaligned at an edge of the laminated substrate. The laminated substrate separating device includes a base where the laminated substrate is disposed thereon, and a separating tool movably disposed on the base along an axis. The separating tool presses a portion of the first substrate being exposed out of the second substrate at a misaligned edge such that a gap is formed between the first and the second substrates. The separating tool inserts into the gap at the misaligned edge to press the first substrate, such that the second substrate is separated from the first substrate. A method for separating laminated substrate is also provided.