It is an object of the present invention to provide an infra-red light emitting phosphor having an excellent chemical stability and desirable light emitting properties. The infra-red light emitting phosphor is represented by a chemical formula: (A1-x-yNdxYby)VO4, wherein A represents at least one element selected from yttrium (Y), gadolinium (Gd), lutetium (Lu) and lanthanum (La); x and y respectively satisfy the requirements: 0.01≦x≦0.3 and 0.01≦y≦0.4, provided that (x+y)≦0.5 and 0.2≦(y/x)≦6. This vanadate phosphor having the constitution described above can act as an infra-red light emitting phosphor having an excellent chemical stability and desirable light emitting properties.