Diary of a Chambermaid is easily the most overtly angry Buñuel film I have seen so far, not because it is any more cynical or subversive than his other films, but because his consistent worldview is not covered up with the usual satire or outright humor of his other films. I don't mean to say that there aren't stabs at comedy here - most notably the old man's foot fetish which supposedly mirrored Buñuel's own fascination - but even many of the ironic or satiric moments seem so dark as to lose their pleasant zing.
Jeanne Moreau plays the chambermaid who arrives in a small French town, only to be thrown into the various rivalries and scandals of her employers, coworkers, and surrounding neighbors. The movie is saved from total depression - among other things - by Moreau, one of the great actresses of her era. Her guarded charm and the immediately believable way in which every character relates to her is entirely due to her screen presence (she performs similar magic in her greatest role, Catherine in Jules and Jim). She remains likable even when her character is most confusing and certainly not the pious angel some may have expected.
I didn't really understand Moreau's character entirely. Was she the stuck-up city girl everyone seemed to think she was? The truffle scene would seem to imply that was the case. But why would she be interested in marrying the general? More importantly, is she just interested in marrying Joseph so she can reveal him as the murderer of Claire? Her performance is so guarded that it was difficult for me to connect with her. Then again, you may be noticing a pattern in which it is difficult for me to connect with anyone in a Buñuel film.