An ultraviolet ray measuring method using an ultraviolet ray receiving
element having a specific spectral sensitivity. The method includes:
estimating an estimated value of an entire region from the spectral
sensitivity of the ultraviolet ray receiving element and a solar spectral
radiation spectrum; estimating an estimated value of a specific region
from a specific action curve and the spectral sensitivity and the solar
spectral radiation spectrum; and determining specific ultraviolet ray
information by, on the basis of the estimated value of the entire region
and the estimated value of the specific region, correcting an actually
measured value which is measured by the ultraviolet ray receiving
element. Further, specific ultraviolet information, which is obtained on
the basis of sun altitude information, is also corrected.