Cerebral vasospasm, known as complication of subarachnoid hemorrhage complication occurred 4-14 days after subarachnoid hemorrhage. Vasospasm means stenosis of vessels and cerebral vasospasm might inhibit sufficient supply of blood to brain, which causes disturbed consciousness, acroparalysis, speech disability and even death after brain infarction. Detailed mechanism of vasospasm induction remains unclear, however, it is thought that substance in the blood stimulates plasma membranes of vascular membrane cells, inducing inflammatory resposes. We utilize trehalose effects on such inflammatory stimuli, and develop vasospasm-preventing device.