An irradiated section (115b) is formed with light blocking sections (162a and 162b) that block light emitted from a light emitting element, and slits (161) through which the light passes and reaches a light receiving element. When a liquid cartridge is installed in a recording device along a direction (144), the light blocking sections (162a and 162b) and the slits (161) move past a detection position at which the emitted light irradiates. In this way, intensity of light received by the light receiving element, can vary between A0 and A1. On the other hand, because the irradiated section (115b) moves in accordance with the decrease of liquid within a liquid accommodating chamber, how many times the intensity of light becomes A0 or A1 changes in response to the remaining amount of the liquid. Hence, residual amounts of liquid at the time of mounting can be obtained by detecting the number of times the intensity of light becomes A0 and the number of times the intensity of light becomes A1, without necessitating an increase in costs.