In Jainism, control over sensual passions is important. For those on the path of dharma, brahmacharya (celibacy or strict sense-control) is a key ideal.

• Monks and nuns: brahmacharya is mandatory. Masturbation is not allowed because it involves sexual arousal and waste of vital energy, which is contrary to purification and non-attachment.
• Householders (lay followers): sexual restraint is part of ethical conduct and self-discipline. Masturbation is generally discouraged because it stimulates desires and can create karmic bondage. The emphasis is on controlling passions, practicing moderation, and cultivating inner purity.

In both Digambar and Shwetambar traditions, the core aim is to reduce attachment and passions to progress on the spiritual path. If you’re seeking a precise stance for a specific tradition, a qualified Jain teacher in that lineage can give you the exact guidance.

If you’d like, I can point you to a Jain Knowledge page that discusses celibacy and ethical conduct for laypeople and renunciants.