A field test of quantum key distribution (QKD) in the Tokyo QKD Network is described, showcasing a secure communication network in a metropolitan area. The network integrates various QKD schemes to demonstrate secure TV conferencing over 45 km, stable long-term operation, and application to secure mobile phones. The Tokyo QKD Network consists of four access points connected by commercial fibers, with six QKD links using different protocols such as decoy-state BB84, DPS-QKD, and BBM92. The network employs a three-layer architecture with quantum, key management, and communication layers, enabling secure key distribution and management. Key systems from different organizations, including NEC-NICT, TREL, NTT-NICT, Mitsubishi, IDQ, and All-Vienna, were tested, achieving high secure key rates and demonstrating stable operation. The network successfully demonstrated secure TV conferencing, eavesdropping detection, and rerouting of QKD links, highlighting the potential for practical QKD applications in metropolitan areas. The results indicate that QKD can be effectively deployed in real-world environments, offering robust security for high-end applications.A field test of quantum key distribution (QKD) in the Tokyo QKD Network is described, showcasing a secure communication network in a metropolitan area. The network integrates various QKD schemes to demonstrate secure TV conferencing over 45 km, stable long-term operation, and application to secure mobile phones. The Tokyo QKD Network consists of four access points connected by commercial fibers, with six QKD links using different protocols such as decoy-state BB84, DPS-QKD, and BBM92. The network employs a three-layer architecture with quantum, key management, and communication layers, enabling secure key distribution and management. Key systems from different organizations, including NEC-NICT, TREL, NTT-NICT, Mitsubishi, IDQ, and All-Vienna, were tested, achieving high secure key rates and demonstrating stable operation. The network successfully demonstrated secure TV conferencing, eavesdropping detection, and rerouting of QKD links, highlighting the potential for practical QKD applications in metropolitan areas. The results indicate that QKD can be effectively deployed in real-world environments, offering robust security for high-end applications.