To provide a separation method and an analyzer using a moving interference pattern of light for solving the problem that separation with a high number of steps and highly precise analysis cannot be obtained due to a short channel in a conventional method for separating and analyzing components using an electrophoresis force or an optical trapping force in a microfluid device.

The separation method using a moving interference pattern of light comprises using a microfluid device having a liquid core light guide composing a part of a channel, allowing two beams of laser light having different wavelengths to enter from an end surface of the liquid core light guide portion to form a moving interference pattern, and applying an optical gradient force from the moving interference pattern to a sample solution plug that is introduced to the liquid core light guide and rested thereon. This method makes it possible to obtain a sharp chromatogram in a short channel and realizes a highly precise separation and analysis by the microfluid device.