A miniature deformable mirror includes an upper portion, a lower portion, and a spacer. The upper portion includes a frame, an organic thin film, and a reflecting layer. The organic thin film is used as a deformed element and is supported by the frame. The reflecting layer is disposed on the organic thin film used for reflecting incident light. The lower portion includes a conductive substrate. The conductive layer is disposed on the substrate and is used for conducting the driving voltage. The spacer is sandwiched between the upper portion and the lower portion. While voltages are applied, electrostatic forces are generated to deform the organic thin film and reflecting layer. Therefore, a miniature deformable mirror with continuously variable focuses is realized.