The infrared absorption filter of the present invention has a
transmittance of not higher than 30% in the near-infrared region in the
wavelength range of 800 to 1100 nm; a difference of 10% or less between a
maximum value and a minimum value of transmittance in the visible light
region in the wavelength range of 450 to 650 nm; and a transmittance of
not lower than 50% at a wavelength of 550 nm, the filter being so
excellent in environmental stability that after being left to stand in
the air atmosphere at a temperature of 60.degree. C. and a humidity of
95% for 1000 hours, the filter can maintain said spectral property in
said range. Consequently, when used for a plasma display or the like, the
filter can absorb the unwanted infrared rays radiated from the display,
resulting in preventing erroneous operation of a remote control using
infrared radiation even in such a high-temperature and high-humidity
environment. The filter is gray in color so that when placed in front of
a display, the color originated in the display can be seen without
discoloration.