As the Ellen Pao sex discrimination trial continues to captivate Silicon Valley, the law firm representing Ms. Pao has filed a bias case on behalf of another woman against an even bigger target: Facebook.

Chia Hong, who worked for Facebook from 2010 to 2013, said that she faced discrimination, harassment and retaliation — and was eventually fired — because she is a woman and of Taiwanese descent, according to a lawsuit filed Monday in state court in San Mateo County, where the company is based.

Among other specific complaints, Ms. Hong said that she was belittled at work, admonished for taking allowed time off to visit her child at school and ordered to organize parties and serve drinks to male colleagues. She claimed that she was fired from her job as a technology partner in October 2013 despite receiving “satisfactory” performance evaluations and was replaced by a less qualified man.

Ms. Hong’s case was filed by Lawless & Lawless, the same firm that is representing Ms. Pao in her sex discrimination case against Kleiner Perkins Caufield & Byers, a prominent Silicon Valley venture capital firm.

The Pao case, which has been closely watched in Silicon Valley, has brought about a broader conversation about the challenges that women face both in venture capital and the broader, male-dominated technology world.

Ms. Hong’s complaint lacks the salacious details and high financial stakes of the Pao case, but it comes as Facebook and other tech companies are struggling to improve the gender and ethnic diversity of their work forces, in which white men dominate the management ranks.

In a report last June, Facebook said that 69 percent of its overall global work force — including 85 percent of its technology workers — was male. At the management level, 77 percent were men and 74 percent were white. The company pledged to do better, and its chief operating officer, Sheryl Sandberg, has been a high-profile advocate of women’s empowerment through her “Lean In” book and speeches.

In response to Ms. Hong’s suit, Facebook said in a statement: “We work extremely hard on issues related to diversity, gender and equality, and we believe we’ve made progress. In this case we have substantive disagreements on the facts, and we believe the record shows the employee was treated fairly.”