Galliani, who has been with the club for 27 years, revealed that Milan's Champions League clash against Ajax will be his last as vice-president.
"I will resign after the match against Ajax," Galliani told ANSA. "I quit for good reason.
"I understand a generational change but it should not be like that, I deserved more elegance. There has been a severe damage to my image.
"I will resign with or without agreement [on the severance pay]. I'll wait some time before deciding [my future]. My affection for president Silvio Berlusconi is not changed and it won't change."
Milan are currently struggling in 13th place in Serie A this season.