Yes, sperm cells are continuously formed in the seminiferous tubules.
Read the full article on: How are spermatozoa formed? – Phases of spermatogenesis ( 46).

Rebeca Reus
BSc, MSc
Degree in Human Biology (Biochemistry) from the Pompeu Fabra University (UPF). Official Master's Degree in Clinical Analysis Laboratory from the UPF and Master’s Degree about the Theoretical Basis and Laboratory Procedures in Assisted Reproduction from the University of Valencia (UV).