To provide a lubricating device for reducing vibrations of a machine and improving lubricating performance of a cylindrical roller bearing.

An oil feeding passage 19 is disposed to a large diameter shaft portion 3a of a spindle 3. Each end face of the oil feeding passage has an opening, and lubricating oil feed to the opening ends is guided to double rows of circumferential grooves 18 formed on an outer circumference of the large diameter shaft portion 3a. An inner ring 5 with collar of the cylindrical roller bearing 2 rotatably supporting the large diameter shaft portion 3a has guiding collars 5a. A plurality of oil passages 20 connecting the relief portions 5b formed at the root portions of the guiding collars 5a and the circumferential grooves 18 are formed at an interval in a circumferential direction. Therefore, rigidity of the inner ring 5 with collar is increased, and deformation of a raceway surface is prevented to suppress occurrence of vibrations generated from the machine, so that the lubricating oil is sufficiently fed into the cylindrical roller bearing 2.