The Post Office at California crossroads in Finchampstead was targeted overnight.
Police were present shortly after daybreak this morning (Thursday), and the area had been cordoned off.
A hole was visible in the window of the building.
A spokesperson for Thames Valley Police told Wokingham Today: “Thames Valley Police received a report of a burglary at the Post Office on Finchampstead Road at around 3.11am this morning.
“It is yet to be ascertained what was taken from the business.
“The force is conducting a thorough investigation, including obtaining and reviewing CCTV footage.
“Officers are looking for any witness to the offence, or any vehicles seen in the area at the time.
“If anyone has any information or any footage please get in touch by reporting on our website or by calling 101, quoting investigation reference number 43230434991.”