An offender entered a dormitory at Heathfield Girls School in London Road between 12.30pm and 2.30pm.
Once inside he stole various Apple products from four different bedrooms including two laptops, two iPads, an iPhone and an iPod touch.
Thames Valley Police said the offender is white, 6ft 2ins and very skinny.
He has a shaved head but with a full hairline and a drawn face with prominent cheek bones.
He was wearing either small hooped ear rings or studs. He wore a pastel blue zipped hooded top with a light T-shirt underneath and straight blue jeans.
Police are appealing for anybody who has information about this incident or the stolen property.
Anyone with information should call the Thames Valley Police 24-hour non-emergency single number 101 and ask to speak to PC Daniel Hayward of Bracknell Forest Local Police Area.
If you don't want to speak directly to the police you can contact the independent charity Crimestoppers anonymously on 0800 555 111 or online at crimestoppers-uk.org.