There is provided a light shielding apparatus with a light shielding seal 1 that reduces a sliding resistance and, at the same time, improves light shielding property and realizes saving of a space. There is provided a light shielding structure that is provided between a plurality of members 13 and 14, which are arranged to be able to move relatively to each other spaced a predetermined distance apart, and is capable of preventing light from entering from a gap to be formed between these plurality of members 13 and 14, having magnetic force generating means 2 and 3 that are disposed in any one of the above-mentioned plurality of members 13 and 14 and magnetic fluid 4 which is magnetically held by the magnetic force generating means 2 and 3 and contacts the other member and shielding a gap, which is formed between the above-mentioned plurality of members 13 and 14, by the above-mentioned magnetic fluid 4.