The 18-year-old student appeared before West Kowloon Magistracy on Wednesday along with six others aged between 15 and 24 who were charged earlier.
No pleas were taken and all seven were remanded in custody as they were either denied bail or didn’t apply for it.
The case was adjourned until December 17 for the police to examine fingerprints and chemicals found in a hostel room in Tsim Sha Tsui, where officers said suspects had intended to make bombs.
The defendants are being linked to an alleged plot to plant bombs at public facilities such as courtrooms and railways.
They were among 14 people arrested by the police in July. The other seven were not charged.