The present disclosure relates to a memory device having a hybrid insulating layer and a method for preparing the same. In detail, a memory device including a gate electrode on a substrate, a source electrode, and a drain electrode has a hybrid memory insulating layer between the gate electrode and the source and drain electrodes that is polarizable and includes a mixed material of vinyltriethoxysilane and organic matter to lead to hysteresis. According to the present disclosure, a memory insulating layer is formed as a hybrid insulating layer including a mixture of polyvinylphenol as the organic matter and vinyltriethoxysilane to complement the properties of an organic memory whereby increasing memory performance, and it stably operates at both low and high temperatures whereby having a wide usage range.