The invention relates to a collimator and a manufacturing method. The collimator includes a base body of a flat plate shape, wherein the upper surface and lower surface of the base body are parallel to each other, at least a through hole which penetrates through the upper surface and the lower surface and has a pore diameter of 1-100 [mu]m is formed in the base body, and the base body is made of glass. A glass blank plate is prepared by using a glass rod tube nested drawing method, optical cold processing is conducted, and then chemical etching is performed so as to obtain the collimator. After the glass of the collimator is determined, core glass matched with the determined glass is designed, and the core glass is removed through acid etching, wherein the core glass is mainly used as a filling material of micropores during manufacture so as to ensure the roundness of the micropores. Through the collimator, the collimation efficiency of particles and stability of particle movement canbe improved effectively, the scattering angle of the particles is reduced, and conditions for high stability, high reliability and miniaturization of atomic clocks, ray cameras and other precision equipment are created.