Penelitian ini bertujuan untuk menganalisis pengaruh komunikasi interpersonal, fasilitas per-pustakaan dan tata ruang perpustakaan terhadap kualitas pelayanan di UPT Perpustakaan UNNES (Rumah Ilmu). Metode pengumpulan data menggunakan kuesioner, dianalisis menggunakan regresi linier berganda dan statistik deskriptif presentase. Hasil penelitian ini menunjukkan bahwa terdapat pengaruh simultan variabel komunikasi interpersonal, fasilitas perpustakaan dan tata ruang perpusta-kaan terhadap kualitas pelayanan sebesar 61,9%. Secara parsial komunikasi interpersonal berpenga-ruh terhadap komunikasi interpersonal sebesar 11,90%, fasilitas perpustakaan berpengaruh terhadap kualitas pelayanan sebesar 37,82% dan tata ruang perpustakaan berpengaruh terhadap kualitas pela-yanan sebesar 7,34%. Hasil penelitian ini juga menunjukkan bahwa komunikasi interpersonal, fasilitas perpustakaan, dan tata ruang perpustakaan berpengaruh positif dan signikan terhadap kualitas pelayanan.Kata Kunci: Interpersonal Communication; Facilities; Layout; Service Quality; Studies of the service quality of the Universitas Negeri Semarang Library UPT Rumah Ilmu through interpersonal communication, facilities, and spatial layout Abstract: This study aims to analyze the effect of interpersonal communication, library facilities, and library layout on service quality at the UNNES Library (Rumah Ilmu). Data collection methods using questionnaires, analyzed using multiple linear regression and percentage descriptive statistics. The results of this study indicate that there is a simultaneous influence of interpersonal communication variables, library facilities, and library layout on service quality by 61.9%. Partially, interpersonal communication affects interpersonal communication by 11.90%, library facilities affect service quality by 37.82% and library layout affects service quality by 7.34%. The results of this study also show that interpersonal communication, library facilities, and library layout have a positive and significant effect on service quality.