section chief; office head; room manager
Refers to the person in charge of a specific room, section, or office within an organization, such as a laboratory, a school staff room, or a company department. The exact English equivalent depends on the context.
彼は研究所の室長に昇進した。
He was promoted to laboratory manager at the research institute.
室長が会議の日程を調整します。
The section chief will coordinate the meeting schedule.
He will be appointed head of the laboratory next month.
She served as head of the planning office for ten years.